Packaging of MMICs in multilayer LCP substrates

A 13-25-GHz GaAs bare die low noise amplifier is embedded inside a multilayer liquid crystal polymer (LCP) package made from seven layers of thin-film LCP. This new packaging topology has inherently unique properties that could make it an attractive alternative in some instances to traditional metal and ceramic hermetic packages. LCP is a near-hermetic material and its lamination process is at a relatively low temperature (285degC versus >800degC for ceramics). The active device is enclosed in a package consisting of several laminated C0₂ laser machined LCP superstrate layers. Measurements demonstrate that the LCP package and the 285degC packaging process have minimal effects on the monolithic microwave integrated circuit radio frequency (RF) performance. These findings show that both active and passive devices can be integrated together in a homogeneous laminated multilayer LCP package. This active/passive compatibility demonstrates a unique capability of LCP to form compact, vertically integrated (3-D) RF system-on-a-package modules